Effect of stretch on the ultraviolet spectral transmission of one type of commonly used clothing

The spectral ultraviolet (UV) transmission through stockings was measured i n field and laboratory based trials using a spectroradiometer. From these s pectral UV measurements, the ultraviolet protection factor (UFF) was calcul ated. The UPF of stockings measured in the field was generally higher than that measured in the laboratory when using a quartz tungsten halogen light as the UV source. The UPF of 50 denier stockings decreased 868% when stretc hed 30% from their original size. Doctors recommending and patients using h igh denier stockings for patient photoprotection should be aware of the dra matic decrease in UPF when the stocking is in a stretched position, such as over a human leg.